Method of making a bag material and the product thereof



April 17, 1945. 2,374,128

METHOD oF MAKING A BAG MATERIAL AND THE PRODUCT THEREOF c. w. PINCKERT Filed sept. 27, 1945 2 Sheets-Sheet l FIG. I.

FIGZ.

Aprilv 17, 1945.

C. W. yF'INGKERT METHOD OF-MAKING A BAG MATERIAL AND THE PRODUCT THEREQF Filed Sept. 27, 1943 2 Sheets-Sheet 2 Patented Apr. 17, 1945 METHOD oF MAKING A nso mATnnmnnNn s I c. 3C1@.S- .'"lhis invention relates to a method a .bag material randfto the resultingjproducmand `more" specifically to a multiply material and .bag

:having fabric and paper plies. f

- VAmong the several objects ofthe invention may befxioteci the provision of an easily constructed multi-ply material which by means organ .ad- ,hesive lap seam may readilypbe made; upf into bags, ease liners and the like which Will herwa- -terproot the .provision -ofvan article of .the class .f

.described which -hasfan `eilective kseal under ymost yin `the structures vhereinafter described-andthe scope .ofthe .application of ywhich eatedinthe following claims. Y

. Will indi- In the accompanying drawings, in1 which l-isy-il.- `lustrated one of various-possible embodiments .of

. the invention,- l

Fig. l is a diagrammatic view taken on line Ij-l .of Fig. 7 and showing` the offset relatcnshipgbe- .tween certain fabric and paper-webmaterialsas they enter .certain coating and joining apparatus;

Fig. 2 is a cross section showingtheapplicaz tion of an adhesive to .the bottomvof the upper 4web indicated in Figs. land '7, the view being taken online 2-2 ofFig.'l; YFig. 3 isa cross section `showing attachment .of the two upper Webs ofl'ig.v 1,;the `viewlaeing taken online 3-3of Fig. '7; l.;

Fig; 4 is a cross section showing the` application lof a second layerpof adhesive tothe assembly -shown in Fig. 3, theview being taken on .line 4-,4

Fig. 55 is -a cross section showing the application of the bottom-web of Fig. 1 to thefassembly ci Fig. 4, the view beingtaken on lline 5,-f5foi' :Fig 6 is a. erosssection -ofvafseamed .tubegmade lfrom the 'material illustrated in Fig. 5; and, i

'Fig. "I is a diagrammatic line drawing illustrating the coating process used. v f

Similar referencev 1cl'naracters indicate corresponding parts throughout the several views' v of v- "thedrawinga y fina-.now.morepaticularly to Fissi and -7 thelie'sis.shown.atgA;.aweb otpapeuof. a type .suitable-fior.' bag liners. At' 13,;` isvshowna 'web' of Irabriosuchwasfis ordinar,ily ..usedy fcrbag bodies,

for .,exaginple;` avm/.en :cotton-.burlan or fthglike.

`At- Cds .shown .a wey M of.,Palpeifwhich `is prefervf ,ably to .beeomethefoutsideof theflnished bag.

As wlappeaatne .outside-inside relationship in reversed-bombe.. la onshpfshownispreferred- As is;t indicated@ Eig.; `the .webs or ylayers A, eB- and'f are-all .ofi the same width l which 'is equal ttor. $11.81 igirth.V :dimension o f. theA final. bag plus a .certain lapseamfdirnensien to bei indicated. hereafter. respect to onear-iotlher,by equal amounts.. This .is br0uShtf'bQiit1asthey pass*through the coating machineryashowntm Fig- 7. and @e indicated `im .Fia-1.... v1n.- praqne the, offsets aref. of. the order .of `one .to onefandeonefhalf. inches. although this not tube aslimyiting. e'

As indicated in Fig. '1, the paper web A passes edge. -Then on a combining roller 4 the; coated webfA lmeets, withthe. fabric; web. B with ,the offsetfas above established... see1fFig3). This exposesl an `4an-.yexnosedzcoatedinangin. lv of the paper web,v A. Then theazassembly of. the two webs shown -in I Fig. Sprooeeds toaisecond` asphalt coatert which It is to be understood that the various `viewsv are diagrammatic and, Where necessary,.f thick- `nesses are exaggerated in order .to make clear Vfea- .applies :an 'asphalt coat-ing I l -to. the underside of the .fabric layer B. AThis .coating-, falls short of theright-handedge I'jof layer -B by an amount .substantially eouaL-.tothe l .said .offset, thus. ,ex-

posing-an unooated.lcwverl margin I3 ,as shownvin .Fig-L4.' Various means inassociation Withcoatingolls are available lfor,` establishing free marfginssuch aszlhsuch; .as deettors 01 masks. :but

sincefthese means. `are' known it will ,not `be nec' iedxfagainst :the lower-.web ofI 'paper Cso that vone edge Ailifofthis-,paper:comes flush with the done inpressure rollsl I 6.; The other; edgexof v this Vpaper layer C. shownnat lxthus becomes .offset husagthirdfuny the stated margnalamgunt n* 7covered and exposedmargin 2l isjestablished.

- The@ above;v completes the g'nroduction sof; 4the .compositeweb ,of Eig. .5. which .constitutes/.an lin- These webs are successively offset'` with like adhesive 25. Thessphalt-covered margin I and uncoated margin 3| of the inner layer A also become adjacentfto effects.. juncture as shown at 33 in Fig. 6.'-

It is to be understood in connection with the kadhesive stripe.,23 is {placed whichiis preferably per A, would cause substantial shrinkage particularly if impregnated deeply. Unwanted shrinkage in unsupported cloth which is heavily coated with asphalt (particularly if on both sides) occurs because the asphalt is applied at elevated temperature and dries out the moisture in the cloth. By having. the cloth supported by paper at or before the time the enclosing layer of asphalt contacts it, excessive shrinkage is prevented.

Bags made according to the present invention y will protecttheir contents against moisture when submerged in sea water for at least 24 hours. For

application of the asphalt I I (Fig. 4) that it may 'I be controlled so it will not be pressed in v`to tm- I pregnate the fabric I3,r but if impregnation is desired to have asphaltli join with asphalt 3, impregnation should be limited to exclude the marginal' area 5, because asphalt at this region would interfere with the efllcency' of adhesive 25. This diierential impregnation, iff desired, maybe accomiplished by'relieving the pressure vvat the'end of the coating roll which is adjacent to margin 5.

Advantages of the invention areasfollows:

The odset arrangement iforestablishin'g' margins to make an ultimate echelonlappedbag side seam is quite economically brought about in the coating apparatus. All webs are of one width and only one degree of offset needs to be maintained throughout. Thus manufacture is extremely simplined. l

The provision of a. papr'topaper adhesive joint outside of the bag s'eainrasl shown at D in Fig. 6 is advantageous for triniess Since the pa-` per is thinner than` fabric. The fabric-tofabric` joint at provides strength. The paper-topaper joint inside "at "I makes a smooth inside joint. i

Since adhesion betweencloth and pre-coated paper (Figs. 2 and 3) Ais 'not'likelyvtobe'as good as adhesion between pre-coated cloth and'fpaper (lower layers of Figs. 4 and 5), it is desirable to have the latter combination outside for greatest protectionand it is also desirable to have paper joined to paper at the outside lap by means' of the additional adhesive 29, asdis'tinguished from the adhesive I I, because this additional? adhesive 29 may be chosen for' its 'specic seaming purpose. This is a characteristic of the preferred construction since the outer layer of paperv C, in

the assembly process, has been adhered to a precoated layer of cloth (Figs. :4 and `5)', and adhesive 28 may be diierent from adhesive II; whereas the inner layer of [paper vA was itself first coated as shown in Fig. 2 and to this combination was applied the fabric (see Fig. 3), andthe adhesive at 33 is the same as the adhesive 3 throughout the remainder of 'the area between paper A and fabric B. It may be noted that the adhesive at 33 may be of the character. stated because the inside 'paper lap is ultimately under the same inside conditions of pressure from bag contents as the remainder f sheet A. Thus it will be seen thatthe most water-#tight component is at the best location, namely, onthc outside of the bag-tube.

Another feature is' that shrinkage is minimized. This is because the final fabric-enveloping layer of asphalt II is applied tothe fabric B aftersaid y fabric has been attached to the paper A. This coating Il, in the absence of theattached Pathis reason the material when made up as case` liners, which are special forms of bags, is quite useful for marine shipments which are sometimes lost overboard and retrieved, or even intentionally beached by iioating in from a vessel.

vThe term bag, as used herein. is to be construed as covering any enclosures made up from a seamed tubular intermediate product. It: in-

cludes case liners and the like of various shapes.

It will be understood that the end sea-ms required for forming a, bag from the tube of Fig. 6 are made of constructions which are of watertightness commensurate with that indicated in the Fig.-"6 seam. End seams are not so difficult to make water-tight because they are not ordinarily lap seams, and in addition it is ordinarily not expected that they be as fiat as the side seams. In other words, the present side 'seam withal its neat and fiat appearance is as watertight as the heavier forms of end seams used. It is to be understood however that the seam disclosed may be used in other locations on bags than the one indicated.

" In 4view of the above, it will be seen that Athe several objects of the invention are achieved and other' advantageous results attained. 'i

` As many changes could be made in the above constructions without departing from thescop'e of the invention, it is intended that all ymatter Acontained in the above description and shown in lthe accompanying drawings shall be interpreted asillustrative and not in a limiting sense.' if

I claim: Y Y

1. A method of producing 'a multi-ply tubular material for making bags and the like comprising passing a rst web of paper through an-adhesive coaterto 'receive an adhesive coat on one side from edge to edge, passing the adhesively coated web of paper into offset running Aand ,combining engagement with a web of fabric causing one uncovered margin of the fabric to extend from the paper, running the engaged oiset paper and fabric webs through a second adhesive coater and applying adhesive to the back of the fabric from `the edge of its extending margin to a' line spaced from its other oiset edge, subsequentlyV passing the combined paper and fabric web into offset running and combining engagement with a second offsetA paper web one edge of Whichweb is co-linear with said line of adhesive on thefabric and the other edge of which is offset, turningthe margins of the combined layers so that an echelon lap seam is formed wherein the said first web of paper is inside with its margins lapped and joined by some of the adhesivecoat already onit. and

applying additional adhesive stripes to Vjoin the adjacent lapped marginal portions of thejintermediate fabric layer and of the outsidcpaper 2. vA tubular multi-ply structure for bags land the like comprising a fabric layer lapped and joined in the resulting lap byanadhesive stripe therein, a paper liner which is cxteriorl'y covered with a layer of asphalt to which said fabric layer is attached, said liner being lapped on one side of the fabric lap and joined by means of an in` tegral continuation of said layer of asphalt, a

layer of asphalt covering said fabric exteriorly including thepart outside of its lap, and a cover of paper attached to said fabric by said asphalt outside of the fabric, said paper cover being lapped 0n the outside and next to the fabric lap, the lapper portions of the papercover being attached by an adhesive stripe therein, said two adhesive stripes being non-integral with the asphalt joining the fabric layer and the paper cover.

3. A tubular product for bag manufacture and the like comprising an inner paper liner com pletely coated-with adhesive and extended to lap itself to form one part oi a seam wherein the adhesive is integral with and the same as the coat on the remainder of the paper, a layer of fabric attached outside of said asphalt coated paper liner, said fabric being lapped fabric to fabric adjacent to the lapped region of said inner paper sheet, adhesive in the fabric lap, and an outer paper cover sheet adhered to said fabric sheet with the exception of a portion of said outer paper sheet which laps itself, said last-named paper lap having an adhesive therein, the adhesive in the outer paper lap and in the fabric lap comprising different bodies from the bodies of the adhesive on opposite sides of said fabric sheet.

CARL W. PINCKERT. 

